services/billing-aws/src/main/java/com/epam/datalab/core/FilterBase.java
<reponame>ep-infosec/incubator-datalab/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

package com.epam.datalab.core;

import com.epam.datalab.core.parser.ParserBase;
import com.epam.datalab.exceptions.InitializationException;
import com.epam.datalab.exceptions.ParseException;
import com.epam.datalab.model.aws.ReportLine;
import com.google.common.base.MoreObjects.ToStringHelper;

import java.util.List;

/**
 * Abstract module of filtering.
 * See description of {@link ModuleBase} how to create your own filter.
 */
public abstract class FilterBase extends ModuleBase {

    /**
     * Parser.
     */
    private ParserBase parser;

    /**
     * Return parser.
     */
    public ParserBase getParser() {
        return parser;
    }

    /**
     * Set parser.
     */
    public void setParser(ParserBase parser) {
        this.parser = parser;
    }


    /**
     * Initialize the filter.
     *
     * @throws InitializationException
     */
    public abstract void initialize() throws InitializationException;

    /**
     * Return the line for parsing if line is accepted and may be parsed,
     * otherwise return <b>null</b>.
     *
     * @param line the source line.
     * @throws ParseException
     */
    public abstract String canParse(String line) throws ParseException;

    /**
     * Return the list of values for transformation if value is accepted and may be transformed,
     * otherwise return <b>null</b>.
     *
     * @param row the list of values.
     * @throws ParseException
     */
    public abstract List<String> canTransform(List<String> row) throws ParseException;

    /**
     * Return the row of billing report if row is accepted and may be written to target,
     * otherwise return <b>null</b>.
     *
     * @param row the report line.
     * @throws ParseException
     */
    public abstract ReportLine canAccept(ReportLine row) throws ParseException;

    @Override
    public ToStringHelper toStringHelper(Object self) {
        return super.toStringHelper(self)
                .add("parser", (parser == null ? null : parser.getType()));
    }
}
